Shock absorber



July 21,1931. A. kB pnspj 1,815,184

SHOCK ABSORBER i Filed Aug. 21. 1929 6R91 L ld Patented `luly 21, 1931 FFlC ANTHONY n. CASPER, or BUFFALO,

CORPORATION, or BUFFALO,

SHOCK AB SORBER Application led August 21, 1929. Serial No. 387,387.

T his invention relates to a hydraulic shock bsorber of the Houdaille type shown in U. S. Le ters Patent No. 1,627,810 May 10. 1927, and has for its object the 1provision of 'r prox-'ed means for bly-passing some of the "esi tance liquid from one side of a piston to the other and to automatically relieve excess pressure of the resistance liquid under abnormal conditions such for example when m. the resistance liquid becomes stid or slow l i flowing in cold Weather.

Vvlith this end in vienT this invention consists generally in providing the hub of the pistons with a dish valve seat which can be made and assembled more economically than Vthose heretofore in use for forming the bypass of the absorber and also providing a flexible disk valve which cooperates With said valve seat `and is adapted under abnormal 9,@ pressures to be d'elected at its outer edge and 'thereby .automatically increase the port area of the relief or by-pass valve device in order to avoid excessive resistance of the liquid and insure veasy riding of the car under different g5 temperature conditions.

1n the accompanying drawings Figure 1 is a longitudinal section of a shock absorber embodying my improvements, taken on line 1 1 F ig. 2.

3Q. Figur-e 2 is a transverse section taken on line 2*2 Fig. 1.

Fig-ure 3 is a fragmentary longitudinal section, on an enlarged scale, of theby-pass or relief valve mechanism.

35 4 In. the following description similar characters lof reference indicate like part-s in the severa-l :figures of the dra-Wings.

This shock absorber is provided with a hollow cylindrical body consisting preferably 4a of a cylindrical peripheral Wall 10, a rear head 11 formed integrally with the peripheral Wall at the rear en-d thereof and provided With lugs 12 'adapted to be connected with one of two relatively movable parts 4g such as the frame of 'an automobile, and a front Wall 13 connected at its edge With the front end of the peripheral Wall by a screw joint 130.

The interior of this cylindrical body is divided into tiro segmental Working chambers 141, 15 by a sectional partition having its sections 16, 16 arranged diametrically Within the outer part of the body and their inner ends connected by a circular collar 1.7. rlhe latter is provided centrally with an axial opening 18 the rear part of which receives a centering or pilot pin 19 projecting forwardly from the rear Wall of the body While the front part of this opening is vacant to form part of a liquid by-pass between the Working chambers as Will presently appear.

Two Working pistons or Wings 20, 21 oscillate Within these Working chambers, the inner ends of these pistons being connected y a circular hub 22 which engages its periphery With the inner edges of the partition sections While its front end engages with the inner rear side of the rear body Wall 13, as shown in Fig. 1. The hub 22 is formed on the rear or inner end of a rock shaft 23 Which is jonrnaled in a bearing 24; on the central partof the Wall 13 and has its external front end connected with a rock arm 25 Which is connected with the other relatively movable part, such for example as the axle of an automobile upon which the frame of the car is mounted by means ofy a spring system. This arm is compelled to turn with the shaft by a lrey 50 and held against forward movement thereon by a clamping screw nut 51. shown in Fig. 1.

The Working chambers of the bodv are filled with a resistance liquid, such as oil, and during the lonT pressure strokes of the pistons this liquid is permitted to pass With comparative freedom from the low pressure end of each VWorking chamber to the high pressure' .pdl

end of the companion chamber bv a checl: 4

valve controlled passage consisting preferably-of a port 26 arranged in each partition section and provided with a valve seat 27 facing the high pressure end of the respective chamber, and a ball check valve 28 movable toward and from this valve seat.

ln front of the body is arranged a replenishing chamber or reservoir 29 which is adapted to contain a reserve supply of resistance liquid and from the lower end of which this liquid is delivered to the lower ends of the working chambers through one or more replenishing ports 30, in the lower part of the wall 18 and each controlled by a cheek valve 31 which is arranged in the respective port 30 and movable toward and from a valve seat 32 therein which faces the working chambers, as shown in Fig. l. r-iir is permitted to escape from the upper ends of the working chambers into the upper end of the replenishing chamber by vents 33 arranged in the wall 13 at the upper ends of these chambers.

For the purpose of regulating the cushionin effect of the resistance liquid in the shock i absorber in accordance with the load imposed on the same and other variable conditions, valve controlled by-pass means are provided which permit the resistance liquid to flow back and forth between the several ends of the werkingr chambers independently of the check valves in the partition sections which bypass valve means-is Constructed as follows The numeral 84 represents a longitudinal bore formed in the shaft and hub of the pistons and havii g its rear end enlarged to form a circular valve chamber GO which is arranged opposite the pocket or recess formed by the front end of the opening 18 in the collar 17.

On its rear face the hub is provided with two radial grooves leading` from the opening 1S to the periphery of the hub and into the respec ve working chambers adjacent to the high pressure sides of the pistons, these grooves being closed on their rear sides by the front end of the -collar 17 engaging with the rear end of the hub.

ill-.t a distance from the rear end of the hub the same is provided with two radial passages 36. 3G leading from the valv chamber to the periphery of the hub and into the respective working chambers adjacent to the low pressure side of the pistons.

Between the rear and front passages 35, 36 of the hub is arranged a valve seat disk 3? which has a central port or orifice 38 and has the front side of its marginal part engaging` a rearwardly7 facing rabbet shoulder 6l formed in the bore of the hub while the rear side of this marginal part of the same is engafed by an annular retaining flange 62 formed on the rear end of the hub and bent into engagement with the rear side of said valve seat disk. The marginal part of the rear side of this disk is provided with a thickened rim 63 and this has formed therein two notches 64 which are in line with the rear radial grooves or passages 35 so as to place the opening i8 iu communication with the working chambers at points adjacent to the high pressure side of the pistons.

On its front side the valve seat disk is provided with an annular raised valve seat 65 around its portand within the valve chamber is arranged a valve closure disk 66 which is adjustable toward and from the valve seat G5 for varying the effective area of the port or orifice of this valve. Longitudinal movement of the valve closure disk may be effected in various ways but preferably by a valve stem 39 arranged lengthwise in the bore of the hub and shaft and carrying the closure disk its rear end while its front end is connected by a screw joint 40 with the shaft. Upon turning the valve stem by a screw driver en gaging a nick il in the front end of the shaft, the valve closure disk GG will be moved lengthwise so that its margin is arranged nearer to or farther from the valve seat 65 and thereby provide a port area of the desired capacity.

is the pistons oscillate back and forth in the working' chambers some of the resistance liquid pushed back and forth through the eondui t of the by-pass device whereby a dead rr. stance to the movement of the pistons during the high pressure strokes is avoided and the shock is absorbed more gradually.

q For the purpose of enabling the by-pass r eviee to automatically increase its port area when the pressure of the resistance liquid rises above the norm al, due for eXample to the liquid becoming thicker, more viscous or sui vwishT the valve closure disk is made of j iblo material such as thinspring sheet metal. which disk is secured onlv at its center to the valve stem thereby enabling the marginal part of this disk to be flexed out of its normal position when subjected to undue pressure.

lVhen therefore the resistance liquid is thickened unduly in cold weather and iiows freely, the valve closure disk is subjected to a greater pressure as the pistons effect their high pressure strokes and Lat this time the marginal part of the flexible closure disk yields to some extent whereby the effective port area or orice of the liquid metering or controlling device is increased and the liquid is permitted to flow through. the bypass conduits with greater freedom and thus avoid hard and unpleasant action of the shock absorber at this time lVhen the liquid again resumes normal consistency the valve closure disk again returns to itsl normal unfleized condition.

To permit the valve closure disk to operate readily in this manner the same is mounted centrally on the valve stem by proisis viding the latter atits rear end with a reduced shank or neck portion 42 which passes through a central hole in the closure disk and securing a ferrule i-3 on the rear part 'of this shank by upsetting or riveting the rear end of the latter, as shown at 44, thereby confining the closure disk between the iterrule and the shoulder Ll5 formed on the stem between its large front part and its small rear part.

In order to permit the marginal part of thevalve closure disk to be iexed over a maximum part of its area the outer part of the shoulder between the large and small part oi the valve stem is bevelled, as shown at lo in Figs. l and 3, thereby permitting the marginal part of this disk to bend forwardly or toward the right in Fig. 3 under the pressure of the resistance liquid to a greater extent than would be possible if this shoulder were square throughout its entire width.

This form of pressure regulating or metering device is simple in construction, the same is reliable and efficient in operation and not liable to get out of order, and the same automatically compensates for any changes in temperature so that the shock absorber operates uniformly under all weather conditions.

It is to be understood in this connection that when the pistons are moving toward the low pressure ends of the working chambers, opposite to the arrows associated with the pistons in Fig. 2, some of the liquid passes from the low pressure ends of the working chambers past the check valves 28 which open at this time and directly into the high pressure ends of the working chambers and some liquid also passes indirectly Jfrom the low pressure ends of the working chambers successively through the passages 36, valve chamber 60, port 38, opening 18 and passages 35 to the high pressure sides of the piston, whereby a comparatively mild shock absorbing eti'ect is produced. But when the pistons move in the direction indicated by the arrows associated therewith in Fig. 2 during a high pressure stroke the resistance liquid cannot pass through the ports 26 because the valves 28 are closed so that liquid at this time can only escape from the high pressure ends of the working chambers through the passages 85, opening 18, port- 38, chamber and passages 36 to the low pressure ends et the working chambers and thereby cause a more pronounced shock absorbing effect.

I claim as my invention l. A shock absorber comprising a working chamber adapted to contain a resist-ance liquid, a piston movable back and forth in said chamber and having a hub containing a valve chamber and passages leading from said valve chamber to said working chamber, a disk valve seat mounted on the heb at one end of said valve chamber and provided with a port, and a flexible disk valve arranged in said valve chamber and movable toward and from said port and adapted t-o be flexed at its edge.

2. A shock absorber comprising a working chamber adapted to contain a resistance liquid, a piston movable back and Jforth in said chamber and having a hub containing a valve chamber and passages leading from said valve chamber to said working chamber, a disk valve seat mounted on the hub at one end of said valve chamber and provided with a port, and a disk valve arranged in said valve chamber and movable toward and from said port, and constructed of lieXible material and adapted to have its marginal part deflected by abnormal pressure of the resistance liquid and automatically increase the port area of said valve device.

3. A shock absorber having a circular hollow body, partition sections arranged within said body and dividing the same into segmental working chambers which are adapted to contain a resistance liquid, a collar connecting the inner edges or" said partition sections and having a central opening, pistons adapted to oscillate in said working chambers and connected with a hub having a central valve chamber and grooves in its end leading from said central opening in the collar to the periphery of said hub and into said working chambers on opposite sides oi said partition sect-ions, and also provided with radial passages arranged at a distance from said end grooves and leading from said valve chamber to the periphery of said hub and into said working chambers on opposite sides of said pistons, a valve seat disk mounted on the hub between said end grooves and radial` passages and provided with a central port, and a valve for controlling said port.

d. A shock absorber having a circular hollow body, partition sections arranged within said body and dividing the same into segmental working chambers which are adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a central opening, pistons adapted to oscillate in said working chambers and connected with a hub having a central valve chamber and grooves in its end leading from said central opening in the collar to the periphery of said hub and into said working chambers on opposite sides of said partition sections, and also provided with radial passages arranged at a distance from said end grooves and leading from said valve chamber to the periphery of said hub and into said working chambers on opposite sides of said pistons, a valve seat disk mounted on the hub between said end grooves and radial passages and provided with a central port, and a valve Jfor controlling said port, said hub being provided with a rabbet shoulder which is engaged by one side of the marginal part of said valve seat disk and said hub having a retaining flange engaging with the opposite side of said marginal part of the U in its end leading from said central opening in the collar to the periphery of said hub and into said working chambers on opposite sides of said partition sections, and also provided with radial passages arranged at a distance from said end grooves and leading from said valve chamber to the periphery of said hub and into said working chambers on opposite sides of said pistons, a Valve seat disk mounted on the hub between said end grooves and radial passages and provided with a central port, and a valve Jfor controlling said port, said valve seat disk being provided on its rear side Jfacing the collar with a marginal thickened rim which is provided with notches in line with said radial grooves.

6. A shook absorber comprising a hollow circular body, partition sections arranged within the body and dividing the same into segmental working chambers adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a cent-ral opening, pistons adapted to oscillate in said working chambers, a hub connected with said pistons and pro vided with a central valve chamber and with rear passages leading radially from said collar opening to said working chamber and with front passages leading from said valve chamber to said working chambers, a valve -seat disk mounted on the hub between said front and rear passages and provided with a central port, and a valve closure disk arranged in said valve chamber and movable toward and from said port.

7. A shock absorber comprising a hollow circular body, partition sections arranged within the body and dividing the same into segmental working chambers adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a central opening, pistons adapted to oscillate in said working chambers, a hub connected with said pistons and provided with a central valve chamber and with rear passages leading radially from said collar tral port, and a valve closure disk arranged in said valve chamber and movable toward and from said port, and constructed of flexible metal.

8. A shock absorber comprising a hollow circular body, partition sections arranged within the body and dividing the same into segmental working chambers adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a central opening, pistons adapted to oscillate in said working chambers, a hub connected with said pistons and provided with a central valve chamber and with rear passages leading radially from said collar opening to said working chamber and with front passages leading from said valve chamber to said working chambers, a valve seat disk mounted on the hub between said front and rear passages and provided with a central port, and a` valve closure disk arranged in said valve chamber and movable toward and from said port and constructed of flexible metal capable of being deflected at its peripheral edge.

9. A shock absorber comprising a hollow circular body, partition sections arranged within the body and dividing the same into segmental working chambers adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a central opening, pistons adapted to oscillate in said working chambers, a hub connected with said pistons and provided with a central valve chamber and with rear passages leading radially from said collar opening to said working chamber and with front passages leading from said valve chamber to said working chambers, a valve seat disk mounted on the hub between said front and rear passages and provided with a cen tral port, a valve closure disk arranged in said valve chamber and movable toward and from said port, a valve stem adjustable lengthwise in said hub and provided with a reduced rear end upon which said closure disk is mounted, and a bevelled shoulder on said stem engaging with the front side of said closure disk, and a errule secured to the reduced rear'end of said stem and en gaging with the rear side of said closure disk.

l0. A shock absorber comprising a hollow circular body, partition sections arranged within the body and dividing the same into segmental working chambers adapted to contain a resistance liquid, a collar connecting the inner edges of said partition sections and having a central opening, pistons adapted to oscillate in said working chambers, a hub connected with said pistons and provided with a central valve chamber and with rear passages leading radially from said collar opening to said working chamber and with front passages leading from said valve chamber to said working chambers, a valvey seat disk mounted on the hub between said front and rear passages and provided With a central port, a valve closure disk arranged in said valve chamber and movable toward and from said port, a. hollow rock shaft journaled in a bearing on said body and connected with signature.

ANTHONY B. CASPER. 

